Safety buckle construction



Oct. 4, 1966 A. F. SPRANGER SAFETY BUCKLE CONSTRUCTION Filed May 7, 1964 48 lz/sl/ 2 1L310 44 INVENTOR ALFRED F. SPRANGER BY KM W n W ATTORNEYS United States Patent 3,276,084 SAFETY BUCKLE CONSTRUCTION Alfred F. Spranger, P.0. Box 191, East Detroit, Mich. Filed May '7, 1964, Ser. No. 365,593 2 Claims. (Cl. 24171) This invention relates to a buckle construction for a belt and more particularly for a safety belt for use in vehicles to secure a passenger in a seat. The belt may also be used in any type buckle as desired, such as parachute buckles, belt buckles for men and women, and so forth.

It is an object of the present invention to provide a belt construction which will securely clamp in a manner such that any strain on the belting material used with the buckle will increase the clamping pressure.

It is a further object of the invention to provide a belt buckle which is readily manipulated by the user and one which is formed of a minimum number of parts to reduce the expense thereof and to simplify the operation.

Another object of the invention is the provision of a belt buckle construction which can be used with a metal securing belt, either directly on the metal or on 'a sheathing material which is over the metal either in the form of a coating on the metal or an envelope of sheathing material.

Another object of the invention is the provision of a belt design in which the holding mechanism is constructed to permit varying degrees of tension on a belt to be secured depending on the requirements.

Other objects and features of the invention relating to details of construction and operation will be apparent in the fol-lowing description and claims.

Drawings accompany the disclosure and the various views thereof may 'be briefly described as:

FIGURE 1, a face view of the buckle construction assembly as it would be viewed from the front.

FIGURE 2, a longitudinal sectional view on line 22 of FIGURE 1 showing the belt in released position.

FIGURE 3, a section similar to that shown in FIGURE 2 with the belt in engaged position.

Referring to the drawings:

A belt housing has a back plate and a face plate 12 connected by side plates 14 and 16, the housing preferably being a unitary construction, and preferably of metal such as an aluminum alloy. The base plate has an extension 18 to which may be secured one end of a belt strap 20. In the present instance, the strap is secured by rivets 22 although this might be accomplished by other suitable securing means or devices which are standard in presently used devices. The flat inner face 24 of the wall 10 has an angle of about 14 to the flat or face 26 of the outer wall 12, and the wedge-shaped recess formed between these inner walls is open at the narrow end to form an entrance recess 28 for receiving the other end 30 of a securing belt. The particular belt shown in the drawings is composed of a central metal core 32 with form of a fiat strap having a plastic sheath 34 on each side and is particularly adapted for use as a safety belt for vehicles and airplanes. Other straps of woven material, plastic or leather can be used.

The face plate of the buckle has slots 36 and 38 extending longitudinally of the buckle at each edge thereof; these slots open into the recess within the walls. Between the angled walls 24 and 26 are two clamping wedge blocks 40 and 42 each having a tapered section as shown in FIG- URES 2 and 3 and each preferably having a serrated surface 44 which can securely clamp the surface of a belt. This surface can be a ripple surface or a surface which has high frictional engagement due to a plurality of small projections thereon.

3,276,084 Patented Oct. 4, 1966 The wedge blocks 40 and 42 are associated to operate together by reason of a cross pin 46 which has a slip fit in opposed passages 48 in the wedges. Other mechanical equivalents of the pin 46 can be utilized such as a tab on one extending into a recess in the other at the edge thereof. Also at the edges of the wedge blocks are side recesses 50 which receive a small coil spring 52 which has extending arms that tend to urge the wedge blocks against the respective inner surfaces 24 and 26. As the parts are viewed in FIGURE 2, the spring 52 is urging the blocks apart from each other so that the belt strap 30 can be inserted through the recess 28 into the space between the wedge blocks 40 and 42. The spring 52 can also serve to insure simultaneous motion of the wedge blocks, thus supplementing the action of the pin 46. The blocks are so disposed in the tapered recess and so engaged by the cross pin 46 that any motion of the blocks into the recess will cause a clamping action on any belt material which is inter-posed between the blocks.

A control handle is provided to shift the wedges from a locking position to a release position. This handle is composed of an actuating plate 60 which has two downturned tabs 62 at each side of the broad portion thereof. These tabs form an anchor point for a pivot pin 64 which passes through these tabs and also through a thickened port-ion of the face plate 12. The lower ends 66 of the tab 62 form a double actuator in the sense that the heel portion thereof moves back and forth in a slot 70 and is positioned to have one side 68 contact one end 72 of that slot to shift the wedge blocks into the converging walls of the inner recess to force the blocks together in a clamping relationship. This position shown in FIGURE 3.

The release motion is effected by the other side 74 of the heel portion of ends 66 which cams the wedge blocks forward in contact with a surface 76 at the other end of slot 70 when the lever plate 60 is lifted as shown in FIG- URE 2. The heel on tabs 62 also holds the wedge blocks captive in the housing. The included angle of 14 between the surfaces 24 and 26 results in a 7 taper for each wedge and this is found to be just above what might be called a self-locking taper. Thus, when the handle 60 is depressed to the position shown in FIGURE 3, the wedges are in a tight lock position which is not released until the handle is raised again. In the meantime, the wedge blocks 40 and 42 are tightly clamped against both sides of the strap or belt 30 in a manner such that increased tension between the straps 20 and 30 will cause an increased pressure against the strap 30 and thus provide an automatic self-locking buckle.

It will be seen that the belt has the advantage that there is a wide area of pressure applied to both sides of the retained strap 30 so that a relatively large surface and a relatively high pressure can be applied to the belt without any highly concentrated small areas of pressure. This is conducive to longer belt life and also permits the use of relatively smooth belt surfaces without danger of slippage. This flat clamping pressure also permits use on a selfwinding belt utilizing the coiling tendency of spring steel. With the flat pressure, there is no tendency to kink the metal. The buckle has tremendous holding power and, as indicated above, the clamping force increases with tension on the straps.

I claim:

1. A locking buckle for a relatively wide, flat, thin strap such as a passenger vehicle safety belt which comprises:

(a) a rigid housing having a wedge-shaped chamber with aligned openings formed by front and rear walls rigidly connected by side walls disposed at an angle toeach other, said front wall having an opening extending to said chamber,

(b) a pair of opposed wedges in said chamber slidable therein from a separated position to a closed position,

(0) means operably connecting said wedges to cause simultaneous sliding thereof,

(d) spring means operating simultaneously on said wedges to force them apart and against the front and rear walls respectively, and

(e) positive locking means comprising a lever pivoted on said housing for shifting said Wedges in said chamber, said lever having an arm projecting through said opening in the front wall of said housing and into a cam recess in one of said wedges to hold said wedges captive in said housing and to forcibly shift said wedges to a separated or a closed position to respectively release or clamp a strap passing through said aligned openings between said wedges.

2. A locking buckle for a relative w-ide, flat thin strap such as 'a passenger vehicle safety belt which comprises:

(a) a housing having a wedge-shaped chamber with fore and aft openings formed by front and rear Walls connected by side Walls, said front wall having an opening extending to said chamber,

(b) a pair of opposed wedges in said chamber slidable therein from a separated position to a closed position,

(0) a first recess in each of said Wedges adjacent a side wall position to oppose the other recess,

(d) spring means disposed in each of said first recesses to urge said wedges to a separated position,

(e) a second recess in each of said wedges positioned to oppose the other second recess,

(f) alignment means slidable in said opposed second recesses to maintain said wedges in opposed relationship,

(g) means pivoted on said housing for shifting said wedges in said chamber comprising an operating lever having an arm projecting through said opening in the front wall of said housing and into a cam recess in one of said wedges to hold said wedges captive in said housing and forcibly shift said wedges to a separated or a closed position to respectively release or clamp a strap passing through said fore and aft openings between said wedges.

References Cited by the Examiner UNITED STATES PATENTS 824,556 6/1906 LoWry et a1. 24136 1,708,979 4/1929 Usher 24-426 2,066,094 12/ 1936 Crawford.

FOREIGN PATENTS 18,307 1899 Great Britain. 706,541 3/ 1954 Great Britain.

WILLIAM FELDMAN, Primary Examiner.

E. SIMONSEN, Assistant Examiner. 

1. A LOCKING BUCKLE FOR A RELATIVELY WIDE, FLAT, THIN STRAP SUCH AS A PASSENGER VEHICLE SAFETY BELT WHICH COMPRISES: (A) A RIGID HOUSING HAVING A WEDGE-SHAPED CHAMBER WITH ALIGNED OPENINGS FORMED BY FRONT AND REAR WALLS RIGIDLY CONNECTED BY SIDE WALLS DISPOSED AT AN ANGLE TO EACH OTHER, SAID FRONT WALL HAVING AN OPENING EXTENDING TO SAID CHAMBER, (B) A PAIR OF OPPOSED WEDGES IN SAID CHAMBER SLIDABLE THEREIN FROM A SEPARATED POSITION TO A CLOSED POSITION, (C) MEANS OPERABLY CONNECTING SAID WEDGES TO CAUSE SIMULTANEOUS SLIDING THEREOF, (D) SPRING MEANS OPERATING SIMULTANEOUSLY ON SAID WEDGES TO FORCE THEM APART AND AGAINST THE FRONT AND REAR WALLS RESPECTIVELY, AND (E) POSITIVE LOCKING MEANS COMPRISING A LEVER PIVOTED ON SAID HOUSING FOR SHIFTING SAID WEDGES IN SAID CHAMBER, SAID LEVER HAVING AN ARM PROJECTING THROUGH SAID OPENING IN THE FRONT WALL OF SAID HOUSING AND INTO A CAM RECESS IN ONE OF SAID WEDGES TO HOLD SAID WEDGES CAPTIVE IN SAID HOUSING AND TO FORCIBLY SHIFT SAID WEDGES TO A SEPARATED OR A CLOSED POSITION TO RESPECTIVELY RELEASE OR CLAMP A STRAP PASSING THROUGH SAID ALIGNED OPENINGS BETWEEN SAID WEDGES. 